A man accused of repeatedly stalking a female staff member at Hampton Bays High School had ammunition in his pocket and a rifle in his car on the school's campus Tuesday, according to authorities.

Southampton Town Police say 46-year-old Todd Tuttle, of Hampton Bays, claimed to be watching his son's lacrosse game on the high school's athletic field Tuesday afternoon. According to investigators, he wasn't.

"I'm pretty freaked out about that," says Matt Lligui, a senior lacrosse player who was on the field during the incident.

A woman who works at the school called police, saying that Tuttle was stalking her in connection with a family conflict.

Lt. James Kiernan of the town's police department says Tuttle has been harassing the victim for weeks.

"There were a few instances where the person would drive by her residence," he says. 

Police say they found a loaded magazine in Tuttle's pocket and a matching rifle in his car, which was parked at the school.

Tuttle faces several charges, including bringing a weapon onto school grounds, trespassing and stalking.

Authorities placed the school on modified lockdown during the investigation. There were no injuries.

"Guns on school grounds is a very high priority for us," Lt. Kiernan says. "The investigation will be ongoing."

Southampton police are asking anyone with information about the case to call them at 631-702-2230.

Tuttle was held on $10,000 bail.